I had the privilege of watching two class acts this week. One was the lord chancellor, Kenneth Clarke, whom I interviewed at Gray's Inn for the Radio 4 programme Law in Action. The other was the lord chief justice, Lord Judge, who had the Commons justice committee eating out of his hand.

Judge may look like a kindly 1950s bank manager but he's razor-sharp. One MP told him she had received complaints from judges that they were required to spend as much as 20 minutes filling in forms every time they passed sentence on an offender.

Firstly, the lord chief justice replied, any such complaints should be made to presiding judges – in effect, the judges' line managers – and not to MPs. Secondly, the forms should not take that long to complete. Finally, he told MPs: "You, in parliament, have laid down a requirement that the sentencing council should collect data." So it was all their fault.

As it was for passing over-complicated legislation. Judge flourished a six-page internal guidance note to judges explaining recent changes to the law of provocation in murder. Sexual infidelity no longer justifies a manslaughter plea unless, perhaps, a woman kills her husband when she finds him raping her sister. How were judges expected to explain such subtle distinctions to juries?

But it wasn't all criticism. The lord chief justice offered some thoughtful ways of saving public money. Judges should set time limits for each stage in a criminal trial. And lawyers, he suggested, should be paid more – rather than less – if they completed a five-day case in three days. The additional cost to the legal aid fund would be more than made up by the saving in court time.

There was even a wry joke for the committee of very new-looking MPs. Litigation was now so expensive that ordinary people were forced to settle, however strong their case might be. Hence the old Chinese curse: "May you be involved in litigation when you are in the right."

Judge and Clarke may not see eye to eye on closing individual courts. But they clearly agree that disputes between parents over contact with their children should be taken out of the adversarial court system.

"The adversarial system means winning," Judge said. "And there's no winner in the context of a child case."

The lord chancellor had taken a similar position just a few hours earlier. "The confrontation of adversarial litigation isn't always the best way of dealing with the disputes that follow a matrimonial break-up or arguments over children," Clarke told me.

Both men supported some sort of mediation. But where they differed was in assessing the future of the legal system.

Judge said that it did not have to provide a Rolls-Royce service, provided it didn't break down between London and Nottingham. Clarke dismissed my suggestion that although it would not be as good a system as we'd had in the past, it was the best we could afford.

Indeed, Clarke would not even accept that he was encouraging judges to pass community sentences in order to cut spending. "I personally have never said we're going to save money by diverting more people from prison to the probation service," he pointed out.

I found this curious. Although community punishments need to be properly funded, they cannot possibly be as expensive as keeping people locked up. And he insisted on playing down his plan to reduce the prison population by 3,000 over the next four years, dismissing it as an "exceedingly modest" target.

To some extent, this must be because he is vulnerable to the accusation from Tory voters that he is soft on crime. He has a perfectly good answer to this, which is that prison does not stop people reoffending on release and that other methods may be more effective. But the lord chancellor could stonewall for England.

So I still prefer the plain speaking of the lord chief justice. As Judge said: "We have to face the fact that … the country's bust."

Joshua Rozenberg is a freelance legal writer, commentator and broadcaster